Lighting fixture



Sept. l4, 1937. c, w, FLOOD, JR 2,093,165

LIGHTING FIXTURE Filed Feb. 15, 1936 INVENTOR Charles M27000,

Patented Sept. 14, 1937 ,7 UNITED STATES PATENT OFFICE LIGHTING FIXTURECharles W. Flood, Jr., Philadelphia, Pa. Application February 15, 1936,Serial No. 64,041

2 Claims. (01. 240- 78) The object of the invention is to provideimprovements in lighting fixtures broadly, but more particularly in thetype which is hereinafter described in detail.

Primarily, another and more specific object is to provide a novelsupport for a fixture, which will preclude the casting of shadows bysuch support, especially in the case of the holder of the usual bowl orglobe, such as is present in practically all forms of indirect andsemi-indirect lighting. However, the immediate need for such an improvedfixture is brought about by the relatively recent perfection of theso-called high intensity mercury vapor lamp, and particularly as thesame becomes more widely used in domestic, oifice, auditorium andsimilar illumination, as compared with the illumination of factories,arenas, and the like, wherein the presence of a different color in thesecondary light within the limits of a shadowarea are of lessimportance.

While the improved fixture is by no means limited to use with theabove-mentioned high intensity mercury vapor lamp, its adaptability incombination with such a lamp is so marked, that certain characteristicsof the samewill be referred to, as they relate to or multiply the ad.-vantages arising from the use of such fixture. This lamp is primarily amercury vapor unit, with its long recognized characteristic of emittinglight, which while aiding vision with lessened eye-strain, and thereby,it is said, reducing nervous tension such as is caused by eye-strain,

nevertheless is rich in blue rays but is practically entirely deficientin red, orange and/or yellow rays. To be even more exact, the lightemitted from the lamp is substantially all produced in the center of thevisible spectrum, that is, in the yellowish green area and extendinginto the blue.

This being the case, it has been found highly advantageous to combine aplurality of common metal filament or similar lamps, which are high inred, orange and yellow rays, in the same unit with a high intensitymercury vapor lamp, except that it is advisable to space the zones ofmost intense heat in the former as far as practicable from the latter,in order that said former will permit the cooling of the said latter, asquickly as possible following cessation of the current supplied, so thatthe vapor lamp will be reconditioned as soon as possible for againstarting, it being a characteristic ofsuch a lamp that it cannot againstartyuntil the mercury vapor within it has been first condensed, andthis requires variously from five to fifteen minutes.

ging form. It .is also preferable that such ,sup-

thereto. 7, v

Having thus obtained a lamp group, which as'a unit emits practically afull daylight range of ray color values, it becomes advisable that thereshall be no shadow from which the rays from the mercury vapor lamp areexcluded, as such shadow especially upon some surfaces will bedistinctly off color, as compared with the remainder of the illuminatedarea. a .7 a

More fully stated, the object of the'invention is therefore to provideav lighting fixture, in which 1 a high intensity mercury vapor or otherform of light from onesource iscombined with metal filament or otherform of light from a second source, and in which the color or colorsemitted by the first differs substantially from that of the second, oneof said light sources being centrally or axially positioned, while theother source is spaced radially away from the first, and the two aresuspended within a common nether-imposed bowl or globe, which reflectspractically all, or at least a substantially portion of the rays fromthe combined light sources radially upwardly.

In order to fulfill this object, an immediate supporting element for thefixture unit has been provided, which, instead of being substantiallyrectilinear and in a geometric plane with the axis of thefcentral. lightsource, extends angularly with respect to such axis, as in the case of ain a regular path, or in the case of one or more diagonally extendingelements not confined 'to such a regular geometric figure as that of aspiral, as for instance an alternating or zig-za'gporting element,regardless ,of shape, shall be closely positioned with respect to thepreferably singie, centrally positioned light source, in order that eventhe penumbra of a shadow which would be cast by saidelement from onepoint of 40 saidsource is totally obliterated by the unim pairedillumination-from other points upon the same source, either or bothabove and below such shadow-casting point.

With the objects of the invention, thus stated, 5 the embodiment hereinshown comprises further details of construction, which are hereinafterfully brought out in the following description, when read inconjunctionwith the accompanying drawing, in which Fig. .1 is avertical diametricalsection through a fixture of the improved type, and Fig. 2 is adiagrammatic view, including the central light source within suchfixture and a portion of the supporting. element as related Referring toFig. 1, there is here shown an embodiment of the invention which maycomprise any suitable type of lamp-supporting member, but which memberis here shown as comprising an annular portion I, surrounding adepressed central portion 2, in which latter is positioned any desiredform of lamp receptacle 3, while radially outwardly said annular portionis preferably deflected downwardly to provide a substantially conicalportion 4, to which are secured any desired number of lamp receptacles5, beyond which said supporting member terminates in an outwardlyextending preferably planular flange 6.

Beneath, and removably secured to said supporting member by any suitablemeans I, is any desired form of ornamental cover 8 for said supportingmember, and this cover also comprises a laterally deflected marginalportion 9, which is adapted, when in operative position, to cooperatewith the fiange 6 of said supporting member, so as to grip or clampbetween them the inner annular edge portion Ill of a bowl or globe ll,which may be of any desired shape and construction whether transparent,semi-transparent, or opaque, or a combination thereof.

That portion of the fixture thus described may obviously be supportedeither in upright position, as from the fioor, or other suitablefoundation, or it may be inverted and suspended from the ceiling orother superposed body. In either case, the fixture is designedtooperatively support a preferably single source of light, with the axisof said source coincident with the axis of the fixture, and said sourcebeing illustrated by a tubular high intensity mercury vapor lamp H, inso-called base-down position within the central receptacle 3, whilesurrounding said lamp and in radially spaced relation therewithpreferably a plurality of lamps 13 of another type are positioned, theselast-mentioned lamps being preferably of the well-known metal filamentform, and with their axes extending diagonally outward from saidfirst-mentioned lamp, or in other words, the outer positioned lampsbeing within the confines of the bowl or globe H, but with their hottestportions spaced as far from the mercury vapor lamp as may be feasible.This is in order that the said outer positioned lamps will not seriouslydelay the cooling of the mercury vapor lamp, following a short periodduring which the current to said lamps may be extinguished. In such acase, with the restoration of the electric current, the outer lampswould light immediately, and if more closely grouped would tend toprevent the cooling of the central lamp, which latter condition isnecessary in order to condense the mercury vapor within the same, beforeit can again become lighted, or illuminated, and at present such coolingrequires a substantial lapse of time of from approximately five tofifteen minutes duration.

Now, it will be obvious that this fixture may be used as hereinbeforereferred to in either upright or inverted position, but for purposes ofillustration, it is shown in the drawing as being in inverted position.In this instance, and also for purposes of illustration, there is showna tubular pipe or conduit [4, which represents any available serviceoutlet extending downwardly from the ceiling, as above mentioned, andbeing provided with a downwardly directed cap E of any suitable form,except that said cap is provided with a preferably diagonally extendingbore 75 It, in which is secured in any suitable manner one end of aspirally shaped tube or rod l1, the opposite end of which is normallysecured to the annular portion l of said. lamp supporting member. Whilesaid support element I1 may comprise a rod, it preferably comprises atube through which may extend the current conducting wires, which leadinto the space between the lamp sup porting member and the cover 8, whensuch wires lead to the receptacles 3 and 5 in well-known approvedmanner.

Of particular note is the fact that said tubular, or similar supportingelement, extends co-axially about the central lamp l2, and in relativelyclose proximity thereto, and is preferably of considerably less diameteror transverse width than said lamp, for the purpose hereinafterdescribed. It should also be noted that instead of said supporting tubecomprising a regularly progressive spiral or similar geometrical figure,it may comprise any suitable shape by which it progresses between thesupporting pipe or other element I l, and the said lamp supportingmember l-6.

Referring to Fig. 2, there is here diagrammatically illustrated theresult of providing said supporting tube of a diameter or transversemeasurement substantially less than that of the lamp 92, which itsurrounds or is at least adjacent to. In this diagram, it will at oncebe apparent that the region l8 of complete shadow, or in other words theumbra, is so small as to be practically insignificant, while thepenumbra, or region I9 of partial shadow, such as may be cast upon asurface 25, is characterized by such an extremely small diminution ofillumination, as to be entirely negligible.

In addition to the foregoing, is the fact that by extending the tube lldiagonal1y,.the light emitted by other portions of the lamp l2, eitheror both above and below the portion partially screened by said tube at agiven point, also directly illuminates the area H! of the penumbra uponthe surface 28, so that by reason of this additional fact, it can betruthfully said that the fixture is adequately supported, but by meansof a supporting element which casts no shadow at all.

In the case of a mercury vapor lamp which notoriously emits rays onlyfrom the yellowishgreen through the blue end of the spectrum, the shadowcast by supporting means heretofore in use presents an area, which whenbeing illuminated only by the metal filament lamp l3, produces anundesirable and inharmonious color contrast of relatively distinctyellow or yellowish tint, Whereas with the present device, the blendingof the light rays, emitted from the two sources I2 and I3, normallycooperates to produce a balanced illumination, which can be made to veryclosely approximate, if not actually duplicate, the true white nature ofdaylight. In other words, it produces a synthetic white light.

So far as the improved fixture is itself concerned, it can function inany position. Therefore, mention hereinbefore of upright or invertedposition is merely representative of any position which may be desirableand feasible.

, Having thus described my invention, what I claim asv new and desire toprotect by Letters Patent of the United States is:-

1. A lighting fixture, comprising a superimposed suspension support, adepending spirally shaped tubular wire-conducting element attached tosaid support, a. member carried by a lower portion of said element, abowl carried by said member, a substantially tubular lamp suption ofsaid element, a bowl carried by said member, a substantially tubularnon-filament lamp 7 supported within the spiral of said element, and aplurality of filament lamps also carried by said member radiallyoutwardly from the spiral of said element, all of said lamps beingwithin said how].

CHARLES W. FLOOD, JR. I

